Title:
Electrocatalytic Activity of Strained Pd Nanoshells on Au Cores
Abstract:
The controlled growth of thin metallic films on a foreign support is a powerful approach for tuning their catalytic activity. The reactivity of these systems can be rationalized in terms of the so-called electronic and geometric (strain) effects. Pd-overlayers on Au substrates have received significant attention over the years, particularly in the context of the hydrogen evolution reaction and formic acid (HCOOH) oxidation. In this contribution, we shall describe the reactivity of Pd shells with thickness between 1 and 10 nm, grown on Au nanoparticles, towards key surface sensitive reactions such as CO and HCOOH electro-oxidation as well as CO2 reduction. Selected area electron diffraction studies of the core-shell nanostructures revealed that the relaxation of the effective Pd lattice strain can be quantitatively described in terms of the Matthews theory. Studies based on in-situ FTIR and Differential Electrochemical Mass Spectrometry reveal that the oxidation of adsorbed CO and HCOOH acid in solution are strongly dependent on the effective lattice strain. This parameter also exhibits a strong influence on the Faradaic efficiency for CO2 reduction in solution.
Biography
David J. Fermín is a Reader in the School of Chemistry of the University of Bristol with over 15 years’ experience in dynamic electrochemistry, photoelectrochemistry and nanostructured electrodes. Previously, he held a 6 year Professorial Fellowship awarded by the Swiss National Science Foundation at the Universities of Berne and Bristol. In 2001, he was awarded the Tajima Prize of the International Society of Electrochemistry for his contributions to the fields of photoelectrochemistry and interfaces between two immiscible electrolyte solutions. His current research interests include solar fuels, active layers for photovoltaic systems and nanostructured materials for electrocatalysis.